Photo-physics of light amplification in lead halide perovskites
Low temperature solution-processed Organic-Inorganic Hybrid lead-halide Perovskites (OIHPs) nanocrystals (NCs) are new and emerging class of semiconducting materials that possesses high quantum yields (PLQY), large linear and non-linear absorption cross-sections, tunable emission wavelength via faci...
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| Format: | Thesis-Doctor of Philosophy |
| Language: | English |
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Nanyang Technological University
2020
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| Online Access: | https://hdl.handle.net/10356/144521 |
| _version_ | 1826121994870980608 |
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| author | Tay, Eugene Yong Kang |
| author2 | Sum Tze Chien |
| author_facet | Sum Tze Chien Tay, Eugene Yong Kang |
| author_sort | Tay, Eugene Yong Kang |
| collection | NTU |
| description | Low temperature solution-processed Organic-Inorganic Hybrid lead-halide Perovskites (OIHPs) nanocrystals (NCs) are new and emerging class of semiconducting materials that possesses high quantum yields (PLQY), large linear and non-linear absorption cross-sections, tunable emission wavelength via facile halide substitutions/exchanges. These properties make OIHP NCs the ideal candidate for light-emitting applications such as LEDs and lasing. Although preliminary reports showed a consistent trend of low (sub μJcm−2) ASE and lasing thresholds, these NC ensembles suffer from ambient air and moisture attacks, causing degradation and inevitably imposes stringent storage and operation conditions. Furthermore, the main fundamental photo-physics behind its optical gain is still not well understood. Therefore, in this thesis, we focus on (I) proposing a synthetic treatment during the Ligand-Assisted RePrecipitation (LARP) of Methyl Ammonium Lead Bromide (CH3NH3PbBr3) NCs in order to improve its surface passivation, (II) using Photoluminescence (PL) and Time-Resolved Photoluminescence (TR-PL) spectroscopy to characterize its ASE/lasing properties and (III) elucidating its carrier dynamics leading to population inversion and subsequently light amplification via spin-dependent Pump-Probe techniques. Specifically, we show that the bound excitons (BX) in CH3NH3PbBr3 NCs play a crucial role in the formation of zero-spin biexcitons (XX) with low biexciton binding energies (EBXX ~ 20meV), which are responsible for intrinsically spin-unpolarized optical gain mechanisms. |
| first_indexed | 2024-10-01T05:41:15Z |
| format | Thesis-Doctor of Philosophy |
| id | ntu-10356/144521 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:41:15Z |
| publishDate | 2020 |
| publisher | Nanyang Technological University |
| record_format | dspace |
| spelling | ntu-10356/1445212023-02-28T23:46:48Z Photo-physics of light amplification in lead halide perovskites Tay, Eugene Yong Kang Sum Tze Chien School of Physical and Mathematical Sciences tzechien@ntu.edu.sg Science::Physics Low temperature solution-processed Organic-Inorganic Hybrid lead-halide Perovskites (OIHPs) nanocrystals (NCs) are new and emerging class of semiconducting materials that possesses high quantum yields (PLQY), large linear and non-linear absorption cross-sections, tunable emission wavelength via facile halide substitutions/exchanges. These properties make OIHP NCs the ideal candidate for light-emitting applications such as LEDs and lasing. Although preliminary reports showed a consistent trend of low (sub μJcm−2) ASE and lasing thresholds, these NC ensembles suffer from ambient air and moisture attacks, causing degradation and inevitably imposes stringent storage and operation conditions. Furthermore, the main fundamental photo-physics behind its optical gain is still not well understood. Therefore, in this thesis, we focus on (I) proposing a synthetic treatment during the Ligand-Assisted RePrecipitation (LARP) of Methyl Ammonium Lead Bromide (CH3NH3PbBr3) NCs in order to improve its surface passivation, (II) using Photoluminescence (PL) and Time-Resolved Photoluminescence (TR-PL) spectroscopy to characterize its ASE/lasing properties and (III) elucidating its carrier dynamics leading to population inversion and subsequently light amplification via spin-dependent Pump-Probe techniques. Specifically, we show that the bound excitons (BX) in CH3NH3PbBr3 NCs play a crucial role in the formation of zero-spin biexcitons (XX) with low biexciton binding energies (EBXX ~ 20meV), which are responsible for intrinsically spin-unpolarized optical gain mechanisms. Doctor of Philosophy 2020-11-11T01:28:17Z 2020-11-11T01:28:17Z 2020 Thesis-Doctor of Philosophy Tay, E. Y. K. (2020). Photo-physics of light amplification in lead halide perovskites. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/144521 10.32657/10356/144521 en This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0). application/pdf Nanyang Technological University |
| spellingShingle | Science::Physics Tay, Eugene Yong Kang Photo-physics of light amplification in lead halide perovskites |
| title | Photo-physics of light amplification in lead halide perovskites |
| title_full | Photo-physics of light amplification in lead halide perovskites |
| title_fullStr | Photo-physics of light amplification in lead halide perovskites |
| title_full_unstemmed | Photo-physics of light amplification in lead halide perovskites |
| title_short | Photo-physics of light amplification in lead halide perovskites |
| title_sort | photo physics of light amplification in lead halide perovskites |
| topic | Science::Physics |
| url | https://hdl.handle.net/10356/144521 |
| work_keys_str_mv | AT tayeugeneyongkang photophysicsoflightamplificationinleadhalideperovskites |